U.K. Ministry of Home Security, "Your Home as an Air Raid Shelter", 1940. With extracts from other relevant documents, including the official 1941 "Shelter at Home" book which shows how to construct proof tested indoor wooden scaffold shelters in bedrooms to resist the debris load from house collapse (which is similar regardless whether a house collapses due to chemical explosive or nuclear blast). This Blitz proved sheltering handbook formed a basis for all subsequent U.K. civil defence, including "Protect and Survive", which was substantiated by information obtained from tests using chemical and nuclear weapons, and Blitz experience. Included also is experimental proof of advice on making gas proof refuge rooms, which keep out sarin nerve gas until it has evaporated and dispersed outdoors. It is still of use today for practical sheltering in the civil war in Syria, where physical damage and gases like sarin are claiming lives.